Sunderland virtually guaranteed themselves a Premiership place next season with this convincing victory over Birmingham City, whose inept performance surely put paid to their last, lingering hope of finding a place in the play-offs.

Sunderland's eagerness to strike an early blow resulted in an injury to Craig Russell, who tumbled over the City keeper and Michael Johnson and stayed off the field briefly for treatment to his leg. It was City, however, who were soon in need of treatment - for shock.

After 17 minutes, Sunderland took the lead with a superb goal from Michael Gray, who accepted a short pass from Paul Stewart to beat Bart Greimink in the City goal with a vicious drive into the top corner from 25 yards.

Greimink was soon picking the ball out of the net again. Sunderland were awarded a free-kick when Gary Poole pushed Gray off the ball. Martin Scott swung the ball over to the far post where Stewart rose to head home firmly for his first goal for Sunderland since joining them on a free transfer from Liverpool.

Stewart should have put Sunderland three up when a low, awkward cross from Gray reached him at the far post, but his attempt to side-foot the ball home was eagerly seized on by Griemink.

Towards the interval City launched some counter-attacks only to find that Sunderland could retreat almost as quickly as they attacked, and City were reduced to long-range, inaccurate efforts.

City's manager, Barry Fry, clearly unimpressed by his side's first-half performance, replaced three of them at the interval. Johnson, Paul Devlin and Andy Legg did not reappear. Their places were taken by Jonathan Hunt, Kevin Francis and Paul Peschisolido.

For Fry, who has used more than 50 players in League games this season, such wholesale substitutions were not a novelty, but it must surely lead City followers to question his managerial style.

Paul Barnes was probably still feeling somewhat confused by the new arrangements. Faced with only the keeper to beat early in the half, he took so long to make up his mind, he was dispossessed by Darius Kubicki at the expense of a corner.

Sunderland tightened their grip after this escape and with an hour gone made City's task virtually impossible. A mistake in the centre circle by Andy Edwards enabled Stewart to roll the ball into the path of Russell, who ran to the edge of the area to deceive the advancing goalkeeper.